Learn SQL from Zero

No installation required. Write and run SQL queries directly in your browser!

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Instant Execution

🎯

Hands-on Learning

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Behind-the-Scenes Insights

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Complete SQL Curriculum

10 comprehensive chapters designed for absolute beginners

01

Introduction to SQL

Understanding databases and SQL from the ground up

  • What is SQL?
  • How databases work
  • Your first query
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02

SELECT & WHERE Clauses

Retrieve and filter data from your database

  • SELECT statement basics
  • WHERE clause filtering
  • Comparison & logical operators
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03

JOINs & Relationships

Combine data from multiple tables

  • INNER JOIN
  • LEFT and RIGHT JOINs
  • Table relationships
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04

Aggregate Functions

Summarize and analyze your data

  • COUNT, SUM, AVG
  • MIN, MAX functions
  • GROUP BY and HAVING
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05

Subqueries & Nested SELECT

Write queries within queries

  • Subquery basics
  • Correlated subqueries
  • IN, EXISTS operators
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06

INSERT, UPDATE, DELETE

Modify data in your database

  • Adding new records (INSERT)
  • Updating existing data
  • Deleting records safely
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07

CREATE & ALTER Tables

Design and modify database schemas

  • Creating tables
  • Data types and constraints
  • Altering table structure
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08

Indexes & Performance

Optimize queries for speed

  • How indexes work
  • Creating and using indexes
  • Query optimization
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09

Transactions & ACID

Ensure data integrity and consistency

  • Transaction basics
  • COMMIT and ROLLBACK
  • ACID properties
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10

Advanced SQL Techniques

Master complex queries and patterns

  • Window functions
  • Common Table Expressions (CTEs)
  • Advanced patterns
Start Chapter →

SQL Playground

Write and execute SQL queries instantly in your browser!

SQL Editor
Output
Click "Run Code" to see query results...

About This Course

🎯 For Complete Beginners

No prior database experience needed. We start from absolute zero, explaining schemas, tables, and rows with real-life analogies like spreadsheets or libraries. You'll master the logic before writing a single line of code.

🔍 Behind-the-Scenes Learning

Understand not just HOW to write queries, but WHY they work. Learn what happens in the database engine (parsing, optimizing, executing) when you run SQL. We peel back the curtain on data storage and retrieval.

💻 Browser-Based

Powered by sql.js - SQLite compiled to WebAssembly. Write and run real SQL queries directly in your browser without installing heavy software. It's a fully-contained, risk-free environment for experimentation.

📚 Comprehensive Curriculum

10 detailed chapters covering everything from basic SELECT queries to advanced window functions and CTEs. Each chapter includes hands-on exercises, real-world datasets, and step-by-step solutions to build your confidence.